JP 3932368 B (Patent Literature 1) is given as the background art of the present invention. Patent Literature 1 describes a method for generating plasma and a method for elemental analysis, each comprising the steps of providing a narrow portion in a flow channel made of an insulation material, the narrow portion having a cross-sectional area markedly smaller than a cross-sectional area of the flow channel; filling the flow channel and the narrow portion with a conductive liquid, and thereafter applying an electric field to the narrow portion, to conduct the electric field through the narrow portion, thereby generating plasma at the narrow portion. Patent Literature 1 also describes an apparatus for generating plasma, the apparatus for generating plasma comprising a narrow portion in a flow channel made of an insulation material, the narrow portion having a cross-sectional area markedly smaller than a cross-sectional area of the flow channel; and a means of applying an electric field to the narrow portion to conduct the electric field through the narrow portion; and an apparatus for emission spectroscopic analysis comprising the apparatus for generating plasma.